DULUTH -- The turbulent union of two people whose careers garnered attention in the 1990s ended with a single gunshot in the hallway of a Gwinnett hotel on Tuesday. She was nicknamed for a child's toy, and he a machine gun.

Former U.S. and world cruiserweight boxing champion Ernest "M-16" Mateen, 46, was fatally shot by his ex-wife, R&B singer Kia Jeffries, 37, in what police are calling a self-defense killing. She uses the moniker "Babydoll" in her solo career, after stints with female groups in the 1990s.

The shooting marked the pair's second violent clash involving police in a month.

Police responded to a person shot call about 4:40 a.m. at the Extended Stay Deluxe on Venture Parkway near Duluth, where Jeffries had been living.

Police found Mateen in a third-floor hallway with a shot to his chest. He was able to tell police Jeffries shot him before he died at Gwinnett Medical Center.

Outside the hotel, police found Jeffries with multiple wounds to her face and forehead. Mateen had reportedly beat her with a handgun until he was exhausted, which is when she managed to turn the gun on him and pull the trigger. No charges are expected.

Jeffries was also hospitalized for treatment. She performs under the Babydoll moniker, following stints with obscure 90s groups Oscar and 4Kast and tours backing up artists such as Daryl Hall and Biz Markie.

It was unknown Wednesday how long Jeffries was wed to Mateen or when the relationship started to sour. Jeffries declined comment Wednesday through Kingsley Gardner, CEO of KGM Entertainment.

"She's feeling really down right now," Gardner said in an email.

According to BoxRec, an online boxing encyclopedia, Mateen finished his career 30-12 with 10 knockouts. He retired at age 40 in 2006 after a win in Memphis.

Mateen had active warrants from the Dunwoody Police Department for false imprisonment and battery charges stemming from an Oct. 9 incident with Jeffries.

Dunwoody police Sgt. Mike Carlson said Jeffries had arrived at the police department with visible injuries that day, claiming Mateen had punched and kicked her at her Peachford Circle residence. Mateen was not living with her at the time, Carlson said.

Mateen's father, a mechanic and boxing coach, also died from a gunshot wound.

Earnest Abdul Mateen was shot dead in 1990 at an open-air vegetable market in New York City during an argument, according to the New York Times. He had coached Mateen, his eldest son, to two Golden Gloves championships the late 1980s, the newspaper reported at the time.